Metabolic Engineering of High L-Lysine-Producing Escherichia coli for de Novo Production of L-Lysine-Derived...

Area of Science:

• Metabolic Engineering
• Synthetic Biology
• Biotechnology

Background:

• 5-Aminovalerate (5-AVA), 5-hydroxyvalerate (5-HV), and 1,5-pentanediol (1,5-PDO) are lysine derivatives with broad industrial applications.
• Current large-scale production methods are limited by inefficient synthetic pathways.
• Developing efficient biological routes is crucial for sustainable production of these compounds.

Purpose of the Study:

• To construct and optimize synthetic pathways for 5-AVA, 5-HV, and 1,5-PDO production in *Escherichia coli*.
• To screen key enzymes and engineering strategies for enhanced production yields.
• To establish practical biological routes for industrial-scale synthesis.

Main Methods:

• Enzyme screening and pathway construction in *Escherichia coli*.
• Overexpression of key enzymes including RaiP, GabT, YahK, and CaR.
• Metabolic engineering strategies such as NADPH regeneration and pathway knockout (e.g., *aldp*).

Main Results:

• Engineered strain LER produced 9.70 g/L 5-HV and 8.31 g/L 5-AVA using only RaiP.
• Strain LE05 produced 1.87 g/L 1,5-PDO and 3.85 g/L 5-HV.
• Optimized strain LE02G2 achieved 10.98 g/L 1,5-PDO with a yield of 0.22 g/g glucose via fed-batch fermentation.

Conclusions:

• The engineered pathways, particularly utilizing RaiP, significantly improved the production of 5-HV and 5-AVA.
• Metabolic engineering strategies, including NADPH regeneration and gene knockout, enhanced 1,5-PDO yield and efficiency.
• The study provides a foundation for the practical bio-production of 5-AVA, 5-HV, and 1,5-PDO.